Compiler output
prog.cpp:33:0: warning: "M_PI" redefined
#define M_PI 3.141592653589793
^
In file included from /usr/include/c++/4.9/cmath:44:0,
from /usr/include/c++/4.9/complex:44,
from prog.cpp:10:
/usr/include/math.h:372:0: note: this is the location of the previous definition
# define M_PI 3.14159265358979323846 /* pi */
^
prog.cpp: In function 'int main()':
prog.cpp:57:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < st.size(); i += 8)
^
